Home

subtyping

Recursive subtyping revealed

14 March 2008 - 3:16pm — admin

The other day I read the article: "Recursive Subtyping revealed". A Functional Pearl by Gapeyev, Levin and Pierce. This is a bit of code I wrote to convince myself of the algorithm described in the paper.

You can get the article here

type at =
    |Top |Nat |Bool |Even | Odd
    |Times of ( at * at )
    |Arrow of ( at * at )
    |Mu of ( string * at )
    |Var of string

module S = SortedList.Make(
    struct
        type t = (at * at)
        let compare = compare
        let hash = Hashtbl.hash

Syndicate content